In U.S. Pat. Nos. 4,341,313 to Doring, and 4,462,500 to Konstant, et al., for example, pallet racks are disclosed in which large pallets, carrying a load of merchandise or other goods, may be stored at a front end of a rack, and then rolled inwardly to make room for another pallet and load. By such apparatus, improvements in warehouse storage procedures can be obtained, in that one may reduce the number of aisles which extend between storage bays, since each pallet may be installed at the front end of the bay and then rolled rearwardly for storage.
When access to a rearwardly positioned pallet is desired, one may simply remove the pallets in front of it with a lift truck or the like to cause the rearwardly positioned pallet to roll forwardly toward the lift truck for access. Thus, such systems can have a greater storage density of pallets when compared with prior systems.
In Konstant U.S. Pat. No. 4,773,546 a pallet rack is disclosed in which pallets may be sequentially placed on first and second wheeled carts, that may be then rolled rearwardly on a pair of rails by subsequent pallets as they are added to the storage bay. The rails used are arranged so that the wheels of the first and second carts roll on separate tracks or sections of the same rail, so that the carts can roll past each other, one above the other, without interference.
By the invention of this application, a modification is provided in which pallets may be placed on a plurality of wheeled carts, two of which can roll on the same rail surface without interference in the operation of either cart in providing multiple pallet storage in a single storage bay. Additionally, by this invention, a single storage bay and pair of rails can provide convenient, accessible storage for pallets using up to four wheeled carts that will roll on the same rails, for convenient storage of a large number of pallets on a single set of rails.